Opus has been on the river as long as I can remember, carvel built with a raised topsides forward of the cockpit, she's unusual and notable.
The 1968 OSTAR Observer Single handed Transatlantic Race lists yacht Opus 32 feet LoA and sailed by Brian Cooke finishing overall 6th but finishing 3rd on corrected time.
Whether this is the same boat or not I don't know, other than that the result information seems to be very scarce, but the boat shows Royal Thames YC membership which back in the 1960's was one of the leading racing clubs of the day.
If anyone has more information please drop me and email.
Random Sixth Boro 9
48 minutes ago